For OUT endpoints, zero-length transfers require MaxPacketSize buffer as per the DWC_usb3 programming guide 3.30a section 4.2.3.3.
This patch fixes this by explicitly checking zero length transfer to correctly pad up to MaxPacketSize.
Fixes: c6267a51639b ("usb: dwc3: gadget: align transfers to wMaxPacketSize") Cc: stable@vger.kernel.org
Signed-off-by: Tejas Joglekar joglekar@synopsys.com --- Changes in v3: - Enclose summary for fixes with " " and no wrap
Changes in v2: - Remove sg patch hunk - Added fixes and stable tag
drivers/usb/dwc3/gadget.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index bed2ff4..6c9b76b 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1119,7 +1119,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc); unsigned int rem = length % maxp;
- if (rem && usb_endpoint_dir_out(dep->endpoint.desc)) { + if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) { struct dwc3 *dwc = dep->dwc; struct dwc3_trb *trb;